1. Field
One or more aspects of embodiments of the present invention are directed toward organic light-emitting devices.
2. Description of the Related Art
Organic light-emitting devices (OLEDs) are self-emitting devices that have advantages, such as wide viewing angles, excellent contrast, quick response, high brightness, and excellent driving voltage characteristics, and can provide multicolored images.
The OLED has a structure including a first electrode disposed on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode sequentially placed on (e.g., formed on) the first electrode. Holes injected from the first electrode are transported to the emission layer through the hole transport region, and electrons injected from the second electrode are transported to the emission layer through the electron transport region. Carriers, such as the holes and electrons, recombine in the emission layer to generate excitons. When the excitons drop (or relax) from an excited state to a ground state, light is emitted.